Photosynthetic characterization of three dominant plant species in the saline-alkaline soil of the Yellow River Delta, China

The diurnal variations of photosynthesis of three dominant species, including Glycine soja, Phragmites australis, and Cynanchum chinensis, in the Yellow River Delta in China have been studied under the same natural conditions using a Li-6400 portable photosynthesis system. The results showed that the curves of diurnal variations of net photosynthetic rate (P-N) of the three plants were different. The diurnal variation of P-N on C. chinensis was a midday depression pattern and had two peaks. However, P-N of G. soja and P. australis showed single-peak curves. The transpiration rate (E) of G. soja was significantly higher than that of P. australis and C. chinensis, both showed single-peak curves. In general, the diurnal course of stomatal conductance (g(s)) followed the same pattern of P-N. A similar diurnal pattern of intercellular CO2 concentration (C-i), vapor pressure deficit (VPD), and water use efficiency (WUE) was observed among different species. VPD showed single-peak curves, while WUE was characterized by double-peak curves, which was contrary to C-i. Linear correlations among photosynthetic variables and key environmental factors indicate high positive correlations between P-N and E, P-N and photosynthetic active radiation, P-N and leaf temperature (T-leaf), P-N and VPD, and between P-N and g(s) except C. chinensis. Negative correlations among P-N and relative humidity, P-N and C-i were found. The irradiance response curves derived from the leaves were substantially affected by different species. C. chinensis showed highest apparent quantum efficiency, followed by P. australis and G. soja, while apparent dark respiration (R-d), convexity (k), light saturation point, and maximum gross CO2 assimilation rate (P-max) of G. soja were higher than those of P. australis and C. chinensis. The irradiance response curve of P-N and WUE of different plant species followed the same order: G. soja>C. chinensis>P. australis. They were both higher than most of other species. It was concluded that plant species adapting to the saline-alkaline habitat showed higher photosynthesis. In addition, G. soja is also effective to improve saline-alkaline soil quality

Breast cancer "tailored follow-up" in Italian oncology units: a web-based survey

urpose: Breast cancer follow-up procedures after primary treatment are still a controversial issue. Aim of this study was to investigate, through a web-based survey, surveillance methodologies selected by Italian oncologists in everyday clinical practice. Methods: Referents of Italian medical oncology units were invited to participate to the study via e-mail through the SurveyMonkey website. Participants were asked how, in their institution, exams of disease staging and follow-up are planned in asymptomatic women and if surveillance continues beyond the 5th year. Results: Between February and May 2013, 125 out of 233 (53.6%) invited referents of Italian medical oncology units agreed to participate in the survey. Ninety-seven (77.6%) referents state that modalities of breast cancer follow-up are planned according to the risk of disease progression at diagnosis and only 12 (9.6%) oncology units apply the minimal follow-up procedures according to international guidelines. Minimal follow-up is never applied in high risk asymptomatic women. Ninety-eight (78.4%) oncology units continue follow-up in all patients beyond 5 years. Conclusions: Our survey shows that 90.4% of participating Italian oncology units declare they do not apply the minimal breast cancer follow-up procedures after primary treatment in asymptomatic women, as suggested by national and international guidelines. Interestingly, about 80.0% of interviewed referents performs the so called "tailored follow-up", high intensity for high risk, low intensity for low risk patients. There is an urgent need of randomized clinical trials able to determine the effectiveness of risk-based follow-up modalities, their ideal frequency and persistence in time

Charge-dependent flow and the search for the chiral magnetic wave in Pb-Pb collisions at root s(NN)=2.76 TeV

Peer reviewe

Photosynthetic and water use characteristics in three natural secondary shrubs on Shell Islands, Shandong, China

Ziziphus jujuba var. spinosa Hu, Periploca sepium Bunge, and Securinega suffruticosa (Pall.) Rehd are mainly natural secondary shrubs on Shell Islands of the Yellow River Delta. The physiological characteristics of leaves of the 3-year-old shrub species, including photosynthesis, apparent quantum yield (AQY), dark respiration rate (R-D), light compensation point (LCP), light saturation point (LSP), transpiration rate (E), and water use efficiency (WUE) and so on, were studied by using a Li-Cor6400 portable photosynthesis system. The results showed that the modified rectangular hyperbola model could simulate the photosynthesis-light response curves better, with a compound correlation coefficient (R-2) greater than 0.996. There were significant differences in the photosynthetic capacity, AQY, R-D, LCP, LSP, E, and WUE among the three shrub species. The three shrub species displayed different photosynthetic ability in the same environment; the photosynthetic capacity of Z. jujuba was 1.49 times that of S. suffruticosa. Z. jujuba had the highest ability to use low light, and its AQY was 0.058, and that of other two species was among ordinary species. The consumption of photosynthetic products of S. suffruticosa was highest and it had the most active physiological metabolism. Z. jujuba had higher shade tolerance, while these three species were photophilous. The sequence of water-consuming ability by transpiration was in the order of Z. jujuba>P. sepium>S. suffruticosa. The water-consuming ability of P. sepium and S. suffruticosa did not show significant correlation with meteorological factors. P. sepium had the highest WUE, followed by Z. jujuba, and S. suffruticosa had the least. The net photosynthetic rate (P-n) and WUE had evident threshold responses to the variations of soil moisture to maintain high efficient water use. The relative moisture content (W-r) of Z. jujuba, P. sepium, and S. suffruticosa was within the range of 36.18-68.89%, 42.31-81.76%, and 46.87-91.62%, respectively, in which three natural secondary shrubs had higher levels of P-n and WUE. In summary, P. sepium had higher development potential, and Z. jujuba had physiological characteristics of higher photosynthetic ability, transpiration, and WUE, and is the most suitable shrub species for afforestation.Ziziphus jujuba var. spinosa Hu, Periploca sepium Bunge, and Securinega suffruticosa (Pall.) Rehd are mainly natural secondary shrubs on Shell Islands of the Yellow River Delta. The physiological characteristics of leaves of the 3-year-old shrub species, including photosynthesis, apparent quantum yield (AQY), dark respiration rate (R-D), light compensation point (LCP), light saturation point (LSP), transpiration rate (E), and water use efficiency (WUE) and so on, were studied by using a Li-Cor6400 portable photosynthesis system. The results showed that the modified rectangular hyperbola model could simulate the photosynthesis-light response curves better, with a compound correlation coefficient (R-2) greater than 0.996. There were significant differences in the photosynthetic capacity, AQY, R-D, LCP, LSP, E, and WUE among the three shrub species. The three shrub species displayed different photosynthetic ability in the same environment; the photosynthetic capacity of Z. jujuba was 1.49 times that of S. suffruticosa. Z. jujuba had the highest ability to use low light, and its AQY was 0.058, and that of other two species was among ordinary species. The consumption of photosynthetic products of S. suffruticosa was highest and it had the most active physiological metabolism. Z. jujuba had higher shade tolerance, while these three species were photophilous. The sequence of water-consuming ability by transpiration was in the order of Z. jujuba>P. sepium>S. suffruticosa. The water-consuming ability of P. sepium and S. suffruticosa did not show significant correlation with meteorological factors. P. sepium had the highest WUE, followed by Z. jujuba, and S. suffruticosa had the least. The net photosynthetic rate (P-n) and WUE had evident threshold responses to the variations of soil moisture to maintain high efficient water use. The relative moisture content (W-r) of Z. jujuba, P. sepium, and S. suffruticosa was within the range of 36.18-68.89%, 42.31-81.76%, and 46.87-91.62%, respectively, in which three natural secondary shrubs had higher levels of P-n and WUE. In summary, P. sepium had higher development potential, and Z. jujuba had physiological characteristics of higher photosynthetic ability, transpiration, and WUE, and is the most suitable shrub species for afforestation